Method and apparatus for immobilizing subjects undergoing mechanical cpr

ABSTRACT

The apparatus for immobilizing and treating a subject includes a suitable apparatus for performing mechanical CPR secured to an immobilization casing. The airtight flexible casing is secured to the apparatus for performing CPR, the casing having variable rigidity which varies as a function of the amount of air within the casing. Two or more slots through the casing permit passage of one or more elements of the CPR apparatus to pass through the casing. One or more incompressible windows may be included in the casing to optimize the performance of mechanical CPR by permitting one or more elements of the subject&#39;s skeleton to contact the CPR apparatus. A device for evacuating the air from within the flexible casing to control the rigidity of the casing is included within the CPR apparatus.

RELATED APPLICATIONS

This application claims priority from U.S. Utility application Ser. No.13/597,099 filed Aug. 28, 2012 now U.S. Pat. No. 8,777,879.

FIELD OF THE INVENTIONS

The inventions described below relate to the field of CPR chestcompression devices.

BACKGROUND

Cardiopulmonary resuscitation (CPR) is a well-known and valuable methodof first aid used to resuscitate people who have suffered from cardiacarrest. CPR requires repetitive chest compressions to squeeze the heartand the thoracic cavity to pump blood through the body. Artificialrespiration, such as mouth-to-mouth breathing or a bag mask apparatus,is used to supply air to the lungs. When a first aid provider performsmanual chest compression effectively, blood flow in the body is about25% to 30% of normal blood flow.

In efforts to provide better blood flow and increase the effectivenessof bystander resuscitation efforts, various mechanical devices have beenproposed for performing CPR. In one variation of such devices, a belt isplaced around the subject's chest and the belt is used to effect chestcompressions. Our own patents, Mollenauer et al., Resuscitation devicehaving a motor driven belt to constrict/compress the chest, U.S. Pat.No. 6,142,962 (Nov. 7, 2000); Sherman, et al., CPR Assist Device withPressure Bladder Feedback, U.S. Pat. No. 6,616,620 (Sep. 9, 2003);Sherman et al., Modular CPR assist device, U.S. Pat. No. 6,066,106 (May23, 2000); and Sherman et al., Modular CPR assist device, U.S. Pat. No.6,398,745 (Jun. 4, 2002), and Escudero, et al., Compression Belt Systemfor Use with Chest Compression Devices, U.S. Pat. No. 7,410,470 (Aug.12, 2008), show chest compression devices that compress a subject'schest with a belt. Our commercial device, sold under the trademarkAUTOPULSE®, is described in some detail in our prior patents, includingJensen, Lightweight Electro-Mechanical Chest Compression Device, U.S.Pat. No. 7,347,832 (Mar. 25, 2008) and Quintana, et al., Methods andDevices for Attaching a Belt Cartridge to a Chest Compression Device,U.S. Pat. No. 7,354,407 (Apr. 8, 2008). Each of these patents is herebyincorporated by reference in their entirety.

In some scenarios in which CPR is required to treat cardiac arrest, isit also necessary to immobilize the subject. The subject may havecoincident injuries, such as a broken vertebrae or broken hip, thatrequire immobilization. The subject may need to be transported overrugged terrain, up or down stairs, or in sitting or upright positions.In these scenarios, it would be beneficial to provide automated CPRchest compressions while also immobilizing the subject. However,conventional immobilization devices do not work well with availablechest compression devices. The components of each device interfere tothe extent that they cannot be combined effectively. One example of adesirable immobilization device is illustrated in Koledin, VacuumImmobilizer Support, U.S. Pat. No. 5,121,756 (Jun. 16, 1992) and Latimeret al., Air Evacuable Support, U.S. Pat. No. 5,154,185 (Oct. 13, 1992)both of which are hereby incorporated by reference in their entirety.These devices comprise bead filled mattresses which, when filled withbeads and air, conform to the subject's shape. After placing the subjecton the mattress, and allowing the mattress to conform to the subject,the mattress may be evacuated to lock the beads in place and transformthe mattress into a rigid backboard which immobilizes the subject.

SUMMARY

The devices and methods described below provide for subjectimmobilization and simultaneous performance of mechanical CPR. The beltdrive platform operates as a generally rigid base that includes all thenecessary mechanisms for performing mechanical CPR. The front surface ofthe platform incorporates an airtight flexible casing partially filledwith beads, pellets or other suitable media (or movable discreteelements, in the terminology used in U.S. Pat. No. 5,154,185). When thecasing contains enough air to be at or near ambient atmosphericpressure, the casing is flexible and the beads are loose and free tomove within the casing or within portions of the casing and conform, orbe made to conform, to the shape of the subject lying on the casing. Asthe air within the casing is evacuated, the beads are forced togetherinto a generally rigid form that has conformed to the subject's body andimmobilizes the subject. Slots through the casing enable the ends of thebelt for performing mechanical CPR to pass through the casing andencircle the subject's thorax for performance of mechanical CPR. One ormore windows in the casing enable skeletal elements of the subject tomake contact with the belt drive platform to optimize the resuscitativework of the platform and belt and not waste energy compressing thebeads.

A suitable belt drive system includes a belt drive platform thatincludes a housing and a drive spool operably attached to the housing aswell as a means for rotating the drive spool, with the means forrotating disposed within the housing and operably attached to the drivespool. A compression belt cartridge engages the belt drive platform. Thecompression belt cartridge including the belt suitable for compressingthe chest of the subject and a spline attached to the belt, wherein thespline is removably attachable to the drive spool, wherein rotation ofthe drive spool tightens the belt to compress the chest. An airtightflexible casing is secured to the housing, the casing having variablerigidity which varies as a function of the amount of air within thecasing. The casing also includes two or more slots to permit passage ofthe belt from the drive belt platform to engage the thorax of thesubject. A means for evacuating the air from within the flexible casingto control the rigidity of the casing is included within the housing. Aplurality of beads are located within the casing, the plurality of beadsadapted to move and conform the casing to support the subject to beimmobilized when the casing is inflated, the plurality of beads adaptedto be rigidly fixed in position when the casing is in a fully evacuatedstate.

A method for immobilizing and treating a subject requiring CPR includesthe steps of providing a mechanical chest compression apparatus andproviding an airtight flexible casing secured to the mechanical chestcompression apparatus, the casing containing a plurality of beadswherein the beads provide variable rigidity which varies as a functionof the amount of air within the casing and providing a vacuum pump forevacuating the air from within the flexible casing to control therigidity of the casing. A subject requiring CPR is placed on the casingand the beads are arranged to support and immobilize the subject. Thesubject is secured to the mechanical chest compression apparatus and theair from within the casing is evacuated by the vacuum pump to rigidlycompresses plurality of beads and immobilize the subject. The mechanicalchest compression apparatus is then activated to repetitively performchest compressions.

A method for immobilizing and treating a subject requiring CPR includesthe steps of providing a mechanical chest compression apparatus andproviding an airtight flexible casing secured to the mechanical chestcompression apparatus, the casing having at least two independentlyoperable portions, each portion containing a plurality of beads whereinthe beads provide variable rigidity which varies as a function of theamount of air within the casing and providing a vacuum pump forevacuating the air from within the independently operable portions ofthe casing to control the rigidity of the portions of the casing. Asubject requiring CPR is placed on the casing and the beads in eachportion are arranged to support and immobilize the subject. The subjectis secured to the mechanical chest compression apparatus and the airfrom within one or more portions of the casing is evacuated by thevacuum pump to rigidly compresses plurality of beads in the evacuatedportions and immobilize the subject. The mechanical chest compressionapparatus is then activated to repetitively perform chest compressions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a prior art chest compression belt fitted on a subject.

FIG. 2 is a schematic cross section of the chest compression device ofFIG. 1.

FIG. 3 is a perspective view of a subject immobilized in a full lengthimmobilization casing while also disposed within an automated chestcompression device.

FIG. 4 is a perspective view of a subject immobilized in an upper bodyimmobilization casing while also disposed within an automated chestcompression device.

FIG. 5 is a side view of the subject and apparatus of FIG. 4.

FIG. 6 is a top view of the automatic chest compression device of FIG.4.

FIG. 7 is a cross-section view of the apparatus of FIG. 6 taken alongA-A.

FIG. 8 is a side view of the apparatus of FIG. 6.

FIG. 9 is a top view of the automatic chest compression device with afull size immobilizer casing.

FIG. 10 is a side view of the apparatus of FIG. 9.

FIG. 11 is a perspective view of a subject immobilized in a full lengthimmobilization casing while also disposed within an automated chestcompression device.

DETAILED DESCRIPTION OF THE INVENTIONS

The apparatus for immobilizing and treating a subject includes asuitable means for mechanically compressing the chest of a subject suchas a belt drive compression system, a piston compression system or avest compression system. A suitable belt drive compression system,similar to the AutoPulse® CPR chest compression device, is illustratedin FIGS. 1 and 2 fitted on a subject 1. Chest compression device 2applies compressions with the belt 3, which has a right belt portion 3Rand a left belt portion 3L, including load distributing panels 4R and 4Ldesigned for placement over the anterior surface of the subject's chestwhile in use, and tensioning portions which extend from the loaddistributing portions to a drive spool, shown in the illustration asnarrow pull straps 5R and 5L. (The entirety of the compression belt isreferred to as a “load distributing band” in the art.) The right beltportion and left belt portion are secured to each other with hook andloop fasteners and aligned with the eyelet 6 and protrusion 7. A bladder8 is disposed between the belt and the chest of the subject. The narrowpull straps 5R and 5L of the belt are spooled onto a drive spool locatedwithin the platform (shown in FIG. 2) to tighten the belt during use,passing first over laterally located spindles 9L and 9R. The chestcompression device 2 includes a belt drive platform 10 and a compressionbelt cartridge 11 (which includes the belt). The platform includes ahousing 12 upon which the subject rests. Means for tightening the belt,a processor and a user interface are disposed within the housing. In thecommercial embodiment of the device, the means for tightening the beltincludes a motor, a drive train (clutch, brake and/or gear box) and adrive spool upon which the belt spools during use.

FIG. 2 is a schematic cross section of the device of FIG. 1, installedon a subject 1. The components include the compression belt 3L and 3R,the load distribution portions of the belt 4L and 4R, the narrow strapportions 5L and 5R, the bladder 8, the spindles 9L and 9R. The drivespool 13 and the spline 14 which fixes the belt to the drive spool arelocated within the housing 12, as is a motor and computer control systemwhich operate to drive the drive spool to spool the belt, therebytightening the belt about the chest and thorax of the subject and aresuscitative rate to accomplish CPR. A load plate 15 is disposed on theplatform (the upper surface of the housing). The anatomical landmarksshown in this Figure include the sternum 16, the spine 17, and the rightand left scapula 18R and 18L of the subject. Referring to the landmarks,the chest compression band is wrapped around the subject such that theload distributing portions are located on the chest (that is, theanterior surface or portion of the thorax), over the sternum, with thenarrow strap portions descending from the load distributing portions towrap around the lateral spindles and thence run to the drive spool. Thelateral spindles are spaced laterally from the medial centerline of thedevice so that they are disposed under, or lateral to, the scapulae ofthe typical subject, so that tightening of the compression band resultsin anterior/posterior compression of the chest.

Our experience with mechanical chest compression suggests that thesubject must remain in a fixed position relative to the housing: Thatis, some anatomical parts of the subject must remain in substantiallyfixed relation to the housing while the sternum is compressed toward thespine. Various other mechanisms or means for chest compression may beused to perform mechanical CPR such as the LUCAS™ chest compressionsystem produced by Physio-Control, Inc. as well as the mechanisms shownin Lach et al., Resuscitation Method and Apparatus, U.S. Pat. No.4,770,164 (Sep. 13, 1988) and in Kelly et al., Chest CompressionApparatus for Cardiac Arrest, U.S. Pat. No. 5,738,637 (Apr. 14, 1998).The entirety of these patents is hereby incorporated by reference.

Referring now to FIG. 3, an immobilization casing such as full lengthflexible casing 1920 may be secured to a suitable automated chestcompression apparatus such as chest compression device 21. Full lengthflexible casing 20 may be partially filled with beads 22 to support andimmobilize subject 23 as shown in Koledin, Vacuum Immobilizer Support,U.S. Pat. No. 5,121,756 (Jun. 16, 2002) the entirety of which is herebyincorporated by reference. Flexible casings may be available indifferent sizes to accommodate for example, extra-large, average andsmall subjects. Vacuum pump 24 is disposed in the housing forcontrolling the amount of air 25 within the flexible casing and fordeflating the flexible casing. Vacuum pump 24 may be any suitable manualor electric means for evacuating the interior of the casing and is influid communication with the interior volume of the casing to enablecontrolled evacuation of the casing to control the rigidity andconformance of the casing and the beads within the casing to the shapeof the subject. The combination of rigid immobilization with mechanicalCPR or other advanced life support techniques provides help to subjectswith multiple problems who would otherwise be impossible to help withconventional immobilization.

The volume of air within flexible casing 20 may also be controlled byvalve 28. When a subject is placed on flexible casing 20 the weight ofthe subject will raise the pressure within the casing and force air 25out through valve 28. Valve 28 may be any suitable valve to allow air 25or other fluid to escape from within the casing. Valve 28 may also beused to permit air to reenter casing 20 to permit readjustment of asubject after air 25 has been evacuated.

In use, subject 23 is placed on casing 19 and beads 22 are arranged tosupport and immobilize the subject and belt portions 3L and 3R areplaced through slots 26A and 26B and then under the subject's axilla(armpits), wrapped around the subject's chest, and secured. Vacuum pump24 is engaged to deflate the casing which rigidly compresses beads 22together and immobilizes the subject. Means for tightening the belt 27is activated to tighten belt 3 repetitively to perform chestcompressions.

Resuscitation apparatus 30 of FIGS. 4 and 5 includes any suitable chestcompression device such as chest compression device 31 which appliescompressions with the belt 32. The chest compression device 31 includesa belt drive platform 33 and a compression belt cartridge 34 (whichincludes the belt 32). The belt drive platform includes a housing 35engaging an upper body airtight flexible casing 36 upon which subject 23rests and is immobilized, a means 37 for tightening the belt, aprocessor 38, a user interface 39 and a vacuum pump 40 such as a vacuumpump disposed in the housing for controlling the amount of air 25 withinthe flexible casing and for deflating the flexible casing. Flexiblecasing 36 is partially filled with movable, discrete elements such asbeads or pellets 44 to support and immobilize the subject. Pellets 44may be made of expanded or solid plastic material, such as polystyreneor polyvinyl chloride and be formed in any shape such as spherical orother suitable regular or irregular shape. The loose beads or pelletswithin an inflated flexible casing permit the casing sides to be movedup against the sides of the subject to cradle and support the subject.The beads are then movable to conform to the contours of the patient'sbody, and also movable to regions where greater rigidity is required.

Additionally, casing 36 may also include one or more portions that maybe independently operable as well as containing specific quantities ofpellets 44 in each portion to control the profile and rigidity of theindependent portions. For example, neck wedge portion 45 may beconfigured with pellets 44 to maintain alignment between the subject'shead 23A and the subject's thorax 23B with the subject's airway 23Coptimally opened as illustrated. Independent operability of the one ormore portions of a casing may be accomplished using multiple vacuumpumps independently controllable by processor 38, or a singe vacuum pumpwith a valving system controllable by processor 38. Means for tighteningthe belt 37 includes a motor 41, a drive train 42 (clutch, brake and/orgear box) and a drive spool 43 upon which the belt spools during use.

Processor 38 is operably connected to vacuum pump 40 to control therigidity of casing 36 and one or more vacuum or pressure sensor such assensor 29 to monitor and provide feedback to the processor. Sensor 29may be operably connected to casing 36 or vacuum pump 40 to monitor thepressure (vacuum) within the casing and therefore its rigidity.Processor 38 may include one or more preset pressure settings for thecasing and for each separate portion of the casing. Sensor 29 may alsoprovide feedback to rescuers when manually controlling the operation ofthe vacuum pump or manually pumping air from the casing.

Referring now to FIGS. 6, 7 and 8, rescue apparatus 50 includes anautomated CPR apparatus such as belt drive platform 51 secured to anupper body airtight flexible casing such as casing 52 secured tohousing. Casing 52 is in fluid communication with vacuum pump 53 whichcontrols the amount of air 54 within casing 52. Casing 52 is sized tosupport a subject from the head to the waist and it includes ridges suchas first ridge 55 and second ridge 56 which provide separation betweenthe subject's arms and the subject's thorax when the subject isimmobilized. Within support ridges 55 and 56 are one or more slots oropenings such as slots 52A and 52B respectively. The openings or slotspermit a compression belt or compression support structure to passthrough the casing to enable mechanical CPR to be performed on animmobilized subject. The casing may also include a neck support portionof the casing to maintain alignment between the subject's head and torsoand open the subject's airway.

To provide optimal compression of the subject's thorax, one or morewindows are provided in casing such as scapular window 57 which areoriented to conform to the scapulae of a subject properly oriented onthe automated chest compression device. The windows are areas of thecasing that are sealed to prevent entry of any beads 22 into the windowspace. This configuration has only one or more layers of incompressiblecasing material 52M between the subject's scapulae and belt driveplatform 51. This configuration enables the chest compression device tocompress the subject's chest without compressing the beads within theimmobilizing casing. One or more incompressible windows may also beprovided to expose load sensors, such as load sensor 58, to thesubject's weight and the compression force without any beads between thesubject and the load sensor or sensors. The load sensors are operablyconnected to the any suitable chest compression means for controllingthe intensity of the chest compressions. One or more support sectionsmay be included to maintain alignment and immobilization of thesubject's skeleton during CPR such as spinal support section 59.

Casing 52 may also include one or more portions that may be haveindependent air content controls as well as specific quantities of beads22 to control the profile of the independent portions such as spinalsupport section 59, neck wedge 60 and or first and second ridges 55 and56 respectively. Independent control enables the head and neck of asubject to be immobilized for performance of intubation separately fromthorax or torso immobilization. Alternatively, the separate casings maybe maintained at different levels of rigidity to accommodate thespecific injuries of the subject.

Referring now to FIGS. 9 and 10, full size casing 70 is configured tosecure a subject's arms to the side of the body with minimal separationbetween the arms and the body in torso portion 70A as well as the fulllength of the subject's legs and feet with leg portion 70B. Scapularwindows such as first scapular window 71 and second scapular window 72are oriented to permit a subject's scapula to contact belt driveplatform 73 and one or more load sensors such as load sensor 74.Scapular windows such as scapular windows 71 and 72 may adopt anysuitable configuration such as the scapular specific shape of secondscapular window 72 or a shape such as first scapular window 71 tooptimize contact between the subject's body and load sensor 74. Theconfiguration of casing 70 also includes a full length spinal support 75and first and second slots 76 and 77 respectively to provide access forbelts or support frames for automated CPR devices.

Referring now to FIG. 11, immobilization and rescue apparatus 80includes full length immobilization casing 81 connected to backboard 82of LUCAS™ chest compression system 83. As discussed above, casing 81 mayalso be a torso only immobilizer and may include one or more windowssuch as window 84 to permit skeletal elements of subject 23 to contactbackboard 82 with no intervening compressible elements. Window 84 willbe formed in casing 81 in the area generally supporting the scapulae andthe area between the scapulae of a subject properly oriented in thecasing. Casings such as casing 81 include one or more access slots orholes such as slots 85A and 85B to permit support structure such assupport legs 86 to pass through the immobilization casing and supportchest compression unit 87 with piston 88 apposing subject's chest 23C.The casing may also include one or more restraining straps 89 to furtherengage and immobilize subject 23.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the inventions. Theelements of the various embodiments may be incorporated into each of theother species to obtain the benefits of those elements in combinationwith such other species, and the various beneficial features may beemployed in embodiments alone or in combination with each other. Otherembodiments and configurations may be devised without departing from thespirit of the inventions and the scope of the appended claims.

We claim:
 1. An apparatus for immobilizing and treating a subjectcomprising: a piston compression system for repetitively compressing thechest of a subject with a chest compression unit driving a piston, thechest compression unit is supported by at least two legs secured to abackboard with the piston apposing the subject's chest; an airtightflexible casing secured to the backboard, the casing containing air andhaving two or more slots to permit passage of the at least two legs ofthe compression system through the casing wherein the casing has avariable rigidity which varies as a function of the amount of air withinthe casing; a vacuum pump for evacuating the air from within theflexible casing to control the rigidity of the casing; a plurality ofbeads located within the casing, the plurality of beads adapted to moveand conform the casing to support the subject when the casing containsair, the plurality of beads adapted to be rigidly fixed in position whenthe casing is in a fully evacuated state.
 2. The apparatus of claim 1further comprising: two separation ridges formed in the casing, eachseparation ridge separating one of the subject's arms from the subject'storso.
 3. The apparatus of claim 2 further comprising: a scapular windowsealed in the casing, the scapular window containing no beads to enablecontact between the subject's scapula and the backboard.
 4. Theapparatus of claim 3 further comprising: a neck support portion of thecasing to maintain alignment between the subject's head and torso andopen the subject's airway.
 5. The apparatus of claim 3 wherein theairtight flexible casing supports and immobilizes the subject from headto foot.
 6. The apparatus of claim 3 wherein the airtight flexiblecasing supports and immobilizes the subject from head to waist.
 7. Theapparatus of claim 3 wherein the casing further comprises: two or moreportions, wherein each portion is independently operable to control aprofile and rigidity of the portion.
 8. The apparatus of claim 7 whereineach of the two or more portions of the casing include a plurality ofbeads.
 9. The apparatus of claim 8 wherein one of the two or moreportions comprises: a neck support portion of the casing to maintainalignment between the subject's head and torso and open the subject'sairway.
 10. The apparatus of claim 1 further comprising: a processor,the processor controlling the operation of the vacuum pump to controlthe rigidity of the casing.
 11. The apparatus of claim 10 furthercomprising: a sensor operably connected to the processor for measuringpressure within the casing to enable the processor to control theoperation of the vacuum pump to control the rigidity of the casing. 12.The apparatus of claim 7 further comprising: a processor, the processorcontrolling the operation of the vacuum pump to independently controlthe rigidity of the two or more portions of the casing.
 13. Theapparatus of claim 1 wherein the piston compression system is supportedby one leg secured to a backboard.
 14. The apparatus of claim 1 furthercomprising: a valve in fluid communication with air in the casing topermit air to leave the casing when the subject is placed on the casing.15. The apparatus of claim 3 further comprising: load sensor secured tothe backboard between the scapular window and the backboard, the loadsensor operably connected to the chest compression unit.
 16. A methodfor immobilizing and treating a subject comprising the steps: providinga means for mechanically compressing the chest of the subject; providingan airtight flexible casing secured to the means for mechanicallycompressing the chest of the subject, the casing having at least twoindependently operable portions, each portion containing air and aplurality of beads wherein the beads provide variable rigidity whichvaries as a function of the amount of air within the portion of thecasing; providing a vacuum pump for evacuating the air from within theat least two independently operable portions of the casing to controlthe rigidity of each portion of the casing; placing the subject on thecasing; arranged the plurality of beads in the at least twoindependently operable portions of the casing to support and immobilizethe subject; securing a subject to the means for mechanicallycompressing the chest of the subject; evacuating air from within one ormore of the at least two independently operable portions of the casingto rigidly compresses plurality of beads in the one or more evacuatedportions and immobilize the subject; and activating the means formechanically compressing the chest to repetitively perform chestcompressions.
 17. The method of claim 16 wherein the step of evacuatingair from one or more of the at least two independently operable portionsof the casing further comprises operating the processor to evacuate aportion of the air from within one or more of the at least twoindependently operable portions of the casing to compress the pluralityof beads in the one or more portions of the casing to a preset level ofrigidity.
 18. The method of claim 16 further comprising the step:measuring the force of mechanical chest compressions using one or moreforce sensors between the means for mechanically compressing the chestand the casing.